Conventional devices to promote safe driving of an automobile include a seat-belt forcibly-wearing device in which a motor of an automobile cannot be started unless a male part of a seat belt of the automobile is attached to a female part thereof (see Patent Documents 1 and 2), a number plate having a function of indicating outside an automobile if alcohol of a predetermined concentration is contained in breath of a driver (see Patent Document 3).
Patent Document 1: Japanese Patent Application Laid-Open No. 50-79022
Patent Document 2: Japanese Patent Application Laid-Open No. 06-239200
Patent Document 3: Japanese Patent No. 3514733